J. Chem. Soc., Perkin Trans. 1, 1999, 2783–2790 2783

This journal is © The Royal Society of Chemistry 1999

Synthesis of cyclic sulfides and allylic sulfides by phenylsulfanyl(PhS-) migration of �-hydroxy sulfides

Jason Eames*ab and Stuart Warren*a

a University Chemical Laboratory, Lensfield Road, Cambridge, UK CB2 1EWb Department of Chemistry, Queen Mary and Westfield College, Mile End Road,

London, UK E1 4NS

Received (in Cambridge, UK) 8th July 1999, Accepted 19th August 1999

New routes to cyclic and spirocyclic sulfides involve aldol reactions of dithioesters or chemoselective Mitsunobureactions of 1,n-diols to give 2-hydroxyalkyl sulfides with a terminal SH group. Treatment with acid givesunrearranged cyclic sulfides, or by rearrangement with PhS-migration, spirocyclic thiolanes and allylic sulfidesin almost quantitative yield. We comment on the effect of the chain length on the mode of cyclisation and onthe surprising differences between an OH group and an SH group as nucleophile towards an episulfonium ion.

In the preceding paper,1 we have reported the type of cyclisationobserved in the acid-catalysed rearrangement of a series of1,n-diols (n = 2 to 12) with an PhS group adjacent to one alco-hol to give single compounds (either rearranged cyclic ethers,unrearranged cyclic ethers or allylic sulfides) in quantitativeyield. Intramolecular capture of episulfonium ions with oxy-gen 2 nucleophiles such as alcohols 3 and esters,4 to give stereo-specifically spirocyclic ethers and lactones is well documented.Slightly less is known about the use of the more basic nitrogen 5

nucleophiles such as amines and sulfonamides to give spiro-cyclic amines.6 For example, treatment of the β-hydroxy sulfideanti-1 with TMSOTf in CH2Cl2 gives the episulfonium ion 2which is captured intramolecularly at the most substituted endto give the spirocyclic amine anti-3 in essentially quantitativeyield (Scheme 1). This type of 1,2-PhS migration occurs stereo-

specifically with inversion of configuration at the migratoryterminus.7

We were interested in extending this cyclisation procedure tothe synthesis of cyclic sulfides and now report the successful useof a sulfanyl (SH) group as an intramolecular nucleophile 8 forthe capture of an episulfonium ion such as 5. The three distinctproducts from the rearrangement of the thiol 4 are the spiro-cyclic sulfide type A (formed with PhS migration by thehybrid (n � 5)-endo–(n � 4)-exo-tet cyclisation) disfavoured byBaldwin’s rule,9 the unrearranged cyclic sulfide of type Bfrom the pure (n � 3)-tet cyclisation (where the position of thePhS group remains unchanged) and the allylic sulfide type C,formed by a [1,2]-PhS shift without cyclisation (Scheme 2).

Initial attempts to form the thiol 4, n = 1 by conversion of thea primary OH group to an SH group by activation and dis-placement proved fruitless; in some cases chemoselective activ-ation of the primary OH group promoted [1,4]-PhS migrationand the formation of allylic sulfides 1,10,11 (by treatment withTsCl in pyridine) and in others oxetanes 12 (under Zirammediated Mitsunobu reaction conditions).13 However, this

Scheme 1 Reagents and conditions: a, TMSOTf, CH2Cl2, �78 �C.

problem was overcome using a masked sulfanyl equivalent(dithioester) as we supposed that reduction of such dithioestersas 8 would give the required thiol 4, n = 1. These thiols wereeventually synthesised by an aldol reaction with dithioesterenolates.14 Formation of the colourless lithium enolate ofthe yellow ethyl dithioester 6 (Fluka 43795) by treatment withn-BuLi at �78 �C and reaction with the aldehydes 7a–c gave thecorresponding yellow dithioesters 8a–c in good yield as shownin Table 1. For successful reduction of 8a–c, slow reverseaddition of the dithioesters 8a–c to a solution of LiAlH4 in etherwas required to prevent a reverse aldol reaction. The thiol 4,n = 1, and the related thiols 9 and 10 were prepared in a reason-able chemical yield (Scheme 3).

Rearrangement of these thiols 4, n = 1, 9 and 10 with eitherTsOH or with TMSOTf in CH2Cl2 gave the type A rearrangedspirocyclic sulfides 11, 12 and 13 in near quantitative yield(Table 1) via the disfavoured hybrid 6-endo–5-exo-tet cyclisation(Scheme 4). This mode of cyclisation to form other spirocyclicheterocycles such as ethers and amines by similar methods is

Scheme 2

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2784 J. Chem. Soc., Perkin Trans. 1, 1999, 2783–2790

Table 1 Yields in the synthesis and rearrangement of the thiols 4, n = 1, 9 and 10

Reaction → aldol

Aldehyde LiAlH4 TsOH TMSOTf

7 R R Dithioesters Thiols Spirocyclic sulfides

7a –(CH2)5– 8a 93% 4, n = 1 99% 11 99% 99%7b –(CH2)4– 8b 82% 9 83% 12 99% 99%7c Me Me 8c 78% 10 79% 13 98% 98%

Table 2 Indentification of thiolanes and thiane by 1H NMR and mass spectra

δ/ppm or J/Hzor mass spectrum

ThiolanesThiane

(abundance) 11 12 13 18 19

δ Ha

Jsyn Ha

Janti Ha

191.1 (PhSC6H10)M � 191.5M � SPh

3.33 (dd)5.4

10.8

0%0%

100%

3.64 (dd)5.28.3

——100%

3.40 (dd)5.7

11.6

——100%

3.60 (t)6.96.9

90%80%

100%

2.59 (dd)2.7

12.0

100%60%

100%

common.4,6 The 1H NMR spectra of these compounds includesa double doublet for Ha with surprisingly dissimilar couplingconstants (see Table 2). A more reliable method for determiningwhich product type was formed was observed from the massspectra; the PhSC2H3 group is the base peak, which is character-istic for rearranged heterocycles of product type A.1

Acid-catalysed rearrangement of the intermediate dithioester8a gave the spirocyclic thiolactone 15 in 85% yield by simplehydrolysis of the thionium ion 14. In the 13C NMR spectrumthe C��O group appears at δC 205 ppm, which is characteristic ofthese thiolactones. Conversely, for dithiocarboxylic esters (suchas ethyl dithioacetate 6) the C��S group surprisingly appears at amuch lower field (δC 250 ppm). Spirocyclic sulfides of this typeare not well known, and some have been synthesised by an alkylmigration in a pinacol rearrangement 15 to give 1-thiaspiro[4.4]-nonanes (e.g. 12), but the same route to the 1-thiaspiro[4.5]-decane (e.g. 11) is very low yielding. Alternatively, we have syn-thesised this type of sulfide using [1,4]-SBn participation anddebenzylation.16

The longer chain thiols 4, n = 2, 3 and 4 were synthesisedfrom the corresponding diols 16, n = 3, 4 and 5 using a chemo-selective Mitsunobu displacement of the primary alcoholinvolving Ziram (zinc dimethyldithiocarbamate, Fluka

Scheme 3

96480) 13 to give the dithiocarbamates 17, n = 2, 3 and 4 in excel-lent yield (Table 3). Subsequent reduction (LiAlH4) gave thelonger chain length thiols 4, n = 2, 3 and 4. These thiols 4, n = 2,3 and 4 were subjected to our standard TsOH rearrangementconditions 4 and these results are presented in Scheme 5. Thethiol 4, n = 2 rearranged exclusively to the thiolane 18 (typeB) in 99% yield, via a pure 5-exo-tet cyclisation (favoured byBaldwin’s rules).9 The 1H NMR spectrum of 18 included a trip-let (J = 6.9 Hz) for Ha which is typical for a five-memberedring,4 as Jgem = Jsyn = Janti (Table 2). The coupling constants inthe spirocyclic thiolanes 11 (type A) are not like this. In themass spectrum, fragmentation between the thiolane and the

Scheme 4 Reagents and conditions: a, TsOH, CH2Cl2, reflux; b,TMSOTf, CH2Cl2, �78 �C.

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J. Chem. Soc., Perkin Trans. 1, 1999, 2783–2790 2785

Scheme 5 Reagents and conditions: a, Ziram, DEAD, PPh3, toluene; b, LiAlH4, Et2O; c, TsOH, CH2Cl2, reflux.

Table 3 Yields in the synthesis and rearrangement of the thiols 4, n = 2, 3 and 4

Reaction → MitsunobuLiAlH4 TsOH

Diols Dithiocarbamate Thiols Sulfides

16; n = 216; n = 316; n = 3

17; n = 217; n = 317; n = 3

85%83%90%

4; n = 24; n = 34; n = 3

76%75%69%

181920

99%99%98%

C6H10SPh group is observed; which is characteristic of thisproduct type (Table 2).1

With longer chain length thiol 4, n = 3, acid-catalysedrearrangement gave the thiane 19, of product type B in nearquantitative yield, via a pure 6-exo-tet cyclisation.1,2 In contrastto 11 and 18, the thiane 19 has a double doublet for Ha

with typical six-membered ring axial–axial (12 Hz) and axial–equatorial (2.7 Hz) couplings. In the mass spectrum, fragmen-tation between the thiane and the C6H10SPh group is againobserved (Table 2). However, in contrast, when the chain lengthwas even longer 4, n = 4, rearrangement gave the allylic sulfide20 (of product type C) in near quantitative yield. The chainlength now appears to be too long for efficient cyclisation, andelimination is now preferred, as the alternative would have beenthe unfavourable thiepine.

However, the alternative product allylic sulfide 20 and 22,n = 2 and 3 (type C) from the rearrangement of thiols 8 was beobtained from the same starting materials 17, simply by revers-ing the order of the reduction and the rearrangement as shownin Scheme 6. Acid-catalysed rearrangement of these dithiocar-

bamates 17, n = 2, 3 and 4 gives the allylic dithiocarbamates 21,n = 2, 3 and 4 by a simple [1,2]-SPh shift without cyclisation.Participation by the C��S group would require the formation ofa medium ring heterocyclic intermediate and so it is less effi-cient than that of a dithioester in 8a. Consequently, the dithio-

Scheme 6 Reagents and conditions: a, TsOH, CH2Cl2, reflux; b,LiAlH4, Et2O.

carbamate functionality serves as a protection against this typeof acid-catalysed cyclisation. Reduction of these allylic dithio-carbamates 21, n = 2, 3 and 4 gave the allylic sulfides 20 and 22,n = 2 and 3 of product type C in good yield (Table 4). Allylicsulfides of this type have potential in [2,3]-sigmatropicrearrangements of the corresponding sulfoxides and sulfoniumsalts.17

ConclusionThe acid-catalysed rearrangement of thiols 4, n = 1, 2, 3 and 4and the corresponding diols 16,1 are broadly rather similar.However, one example is quite different: rearrangement of thiol4, n = 2 gave the thiolane 18 of type B, whereas the diol 16, n = 2gave the tetrahydropyran 25 of type A by attack at the moresubstituted end of the episulfonium ion 24 via a hybrid 6-endo–5-exo-tet cyclisation; 1,2 both reactions occur in quantitativeyield. The alternative type B tetrahydrofuran 26 can be pre-pared by simple ether formation (TsCl–pyridine) from theoriginal diol (Scheme 7).1,2 However, this tetrahydrofuran 26does rearrange under the acid-catalysed reaction conditions(TsOH in CH2Cl2) to give the type A THP 25 in quantitativeyield. Clearly, the THP 25 is the thermodynamic product of thecyclisation of diol 16, n = 2, whereas the THF 26 has beenshown to be the kinetic product—albeit in a 67 :33 ratio 26 :25(determined from the decomposition of a cyclic sulfite).18 Inter-estingly, the much less basic thiolane 18 does not rearrange tothe thermodynamically preferred thiane (type A) in acid andmust be the kinetic product.

In the kinetically controlled cyclisations with SH as a nucleo-phile, it appears that Baldwin’s rules 9 are more important andthe 5-exo-tet is more efficient, than when OH is the nucleophile,

Table 4 Yields in the synthesis of allylic sulfide 20 and 22, n = 2 and 3

Reaction → TsOHLiAlH4

DithiocarbamateAllylic sulfides/Dithiocarbamate

Allylic sulfides/thiols 22

17; n = 217; n = 317; n = 3

21; n = 221; n = 321; n = 3

95%97%96%

22; n = 222; n = 320

82%76%69%

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2786 J. Chem. Soc., Perkin Trans. 1, 1999, 2783–2790

perhaps because the greater nucleophilicity of the SH groupdemands a tighter transition state. Additionally, rearrangementof diol 16, n = 3 gave a mixture of unrearranged THP (typeB) in 59% and the allylic sulfide (type C) in 13% yield,1,10 whilethe thiol 4, n = 3 exclusively gave the type B thiane 19 in nearquantitative yield.

In conclusion, we have shown that the shortest chain thiols 4,n = 1 cyclise to form spirocyclic sulfides 11 of type A, and theintermediate chain length n = 2 gives the unrearranged type Bcyclic sulfides 18. Clearly five-membered ring formation in bothcases is favoured over other ring sizes (four and six). However,six-membered ring formation becomes favoured (to give un-rearranged thiane 19 of type B) over the alternative morestrained seven-membered thiepines of type A. However, allylicsulfides 20 of type C are formed when the chain length n is toolong for efficient cyclisation. The dithiocarbamates 17, n = 2,3and 4 also gave the allylic sulfide 21, n = 2, 3 and 4 withoutcyclisation as the dithiocarbamate functionality serves as aprotection against cyclisation.

ExperimentalAll solvents were distilled before use. Tetrahydrofuran (THF)and ether were freshly distilled from LiAlH4, whilst dichloro-methane (CH2Cl2) and toluene were freshly distilled fromCaH2. Triphenylmethane was used as the indicator for THF.n-BuLi was titrated against diphenylacetic acid before use.All reactions were carried out under nitrogen using oven-dried glassware. Flash column chromatography was carriedout using Merck Kieselgel 60 (230–400 mesh). Thin layerchromatography (TLC) was carried out on commercially avail-able pre-coated plates (Merck Kieselgel 60F254 silica). Protonand carbon NMR spectra were recorded on a Bruker WM 200,WM 250 or WM400. Fourier transform spectrometers wereused with an internal deuterium lock. Chemical shifts arequoted in parts per milllion downfield from tetramethylsilane.Carbon NMR spectra were recorded with broad protondecoupling and Attached Proton Test (ATP). The symbol *after the carbon shift indicates an even number of attachedprotons; i.e., CH2 or quaternary carbons. The symbols i-, o-,m- and p- denote the ipso-, ortho-, meta- and para- positionsrespectively for the phenyl ring (PhS group). Mass spectra wererecorded on a AEI Kratos MS30 or MS890 machine using aDS503 data system for high resolution analysis. All compoundswere isolated using flash column chromatography and wereassumed to have a purity of greater than 98% (determined byNMR).

3-Hydroxy-3-[1�-(phenylsulfanyl)cyclohexyl]-1-sulfanylpropane4, n � 1

A solution of dithioester dithioacetate 8a (0.1 g, 0.293 mmol) inether (5 ml) was slowly added to a stirred solution of LiAlH4

(34 mg, 0.91 mmol) in ether (3 ml) at 0 �C. The solution wasstirred for 1 hour and poured onto ice–brine. NaOH (1 ml,10%) was added and the solution was extracted with ether

Scheme 7 Reagents and conditions: a, TsOH, CH2Cl2, reflux.

(3 × 40 ml). The combined organic extracts were dried (MgSO4)and evaporated under reduced pressure. The residue was puri-fied by flash chromatography on silica gel eluting with lightpetroleum (40–60 �C)–ether (1 :1) to give the thiol 4, n = 1 (80mg, 99%) as an oil; Rf [light petroleum (40–60 �C)–ether (1 :1)]0.55; νmax (film, CDCl3)/cm�1 1580 (SPh); δH(400 MHz, CDCl3)7.67–7.30 (5 H, m, SPh), 3.42 (1 H, dd, J 9.2 and 2.9, CHOH),3.04 (1 H, s, OH), 2.84–2.75 (1 H, m, CHAHBSH), 2.59–2.54(1 H, m, CHAHBSH), 2.03–1.15 (12 H, m, 6 × CH2) and 1.34(1 H, t, J 4.2, SH); δC(100 MHz, CDCl3) 137.3 (m-SPh), 130.1*(i-SPh), 129.1 (p-SPh), 128.9 (o-SPh), 73.3 (CHOH), 61.3*(CSPh), 35.1* (CH2-SH), 30.8*, 30.0*, 26.2*, 22.5*, 21.9* and21.8* (6 × CH2) (Found M�, 282.1099. C15H22OS2 requires282.1112); m/z 282.1 (65%, M), 191.1 (95, C6H11SPh), 173.1 (20,M � SPh), 155.1 (42, M � SPh � H2O), 110.0 (100, PhS � H)and 81.1 (80, C6H11 � H).

4-Hydroxy-4-[1�-(phenylsulfanyl)cyclohexyl]-1-sulfanylbutane44, n � 2

LiAlH4 (74 mg, 1.98 mmol) was added to a stirred solution ofthe dithiocarbamate 17, n = 2 (0.25 mg, 0.66 mmol) in ether (5ml) at 0 �C. The solution was stirred for 12 hours and pouredonto ice–brine. NaOH (2 ml, 10%) was added and the solutionwas extracted with ether (3 × 50 ml). The combined organicextracts were dried (MgSO4) and evaporated under reducedpressure. The residue was purified by flash chromatography onsilica gel eluting with light petroleum (40–60 �C)–ether (1 :1) togive the thiol 4, n = 2 (0.19 g, 76%) as an oil; Rf [light petroleum(40–60 �C)–ether (1 :1)] 0.8; νmax (film, CDCl3)/cm�1 3200 (OH);δH(400 MHz, CDCl3) 7.55–7.25 (5 H, m, SPh), 3.23 (1 H, dd,J 10.0 and 2.2, CHOH), 3.08 (1 H, d, J 2.2, OH), 2.51 (1 H, q,J 7.2, CHAHBS), 2.50 (1 H, q, J 7.2, CHAHBS), 2.04–1.16 (14 H,m, 7 × CH2) and 1.30 (1 H, t, J 7.61); δC(100 MHz, CDCl3)137.2 (m-SPh), 130.1* (i-SPh), 129.0 (o-SPh), 128.8 (p-SPh),74.3 (CHO), 61.8* (CSPh), 31.7* (CH2S), 30.6*, 29.6*, 29.2*,26.2*, 24.7*, 21.8* and 21.8* (7 × CH2) (Found M�, 296.1265.C16H24OS2 requires M, 296.1268); m/z 296.1 (95%, M), 191.1(100, C6H10SPh), 110.0 (70, PhSH) and 81.1 (55, C6H9).

5-Hydroxy-5-[1�-(phenylsulfanyl)cyclohexyl]-1-sulfanylpentane4, n � 3

In the same way as 4, n = 2, the dithiocarbamate 17, n = 3 (50mg, 0.12 mmol) and LiAlH4 (14 mg, 0.37 mmol) in ether (1 ml)gave, after column chromatography on silica gel eluting withlight petroleum (40–60 �C)–ether (1 :1), the thiol 4, n = 3 (29.2mg, 75%) as an oil; Rf [light petroleum (40–60 �C)–ether (1 :1)]0.65; νmax (film, CDCl3)/cm�1 3300 (OH); δH(400 MHz, CDCl3)7.51–7.30 (5 H, m, SPh), 3.23 (1 H, d, J 9.4, CHOH), 3.06 (1 H,s, OH), 2.49 (1 H, q, J 7.5, CHAHBS), 2.48 (1 H, q, J 7.5,CHAHBS), 1.99–1.30 (16 H, m, 8 × CH2) and 1.31 (1 H, t, J 7.7,SH); δC(100 MHz, CDCl3) 137.2 (m-SPh), 130.1* (i-SPh), 129.0(p-SPh), 128.8 (o-SPh), 74.5 (CHOH), 61.9* (CSPh), 34.1*(CH2S), 30.6*, 30.0*, 29.6*, 26.2*, 24.5*, 21.9* and 21.8*(8 × CH2) (Found M�, 310.1428. C17H26OS2 requires M,310.1424); m/z 310.1 (100%, M), 201.1 (20, M � SPh), 191.1(100, C6H10SPh), 109.0 (20, PhSH) and 81.0 (50, C6H9).

6-Hydroxy-6-[1�-(phenylsulfanyl)cyclohexyl]-1-sulfanylhexane4, n � 4

In the same way as 4, n = 2, the dithiocarbamate 17, n = 4 (0.35g, 0.85 mmol) and LiAlH4 (93 mg, 2.54 mmol) in ether (5 ml)gave, after column chromatography on silica gel eluting withlight petroleum (40–60 �C)–ether (1 :1), the thiol 4, n = 4 (0.19 g,69%) as an oil; Rf [light petroleum (40–60 �C)–ether (1 :1)] 0.7;νmax (film, CDCl3)/cm�1 3200 (OH); δH(250 MHz, CDCl3) 7.51–7.27 (5 H, m, SPh), 3.23 (1 H, dd, J 9.3 and 2.3, CHOH), 2.50(2 H, q, J 7.0, CH2S), 2.09–1.08 (20 H, m, 10 × CH2) and 1.31(1 H, t, J 10.6, SH); δC(100 MHz, CDCl3) 137.2 (m-SPh), 130.2

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(i-SPh), 129.0 (p-SPh), 128.8 (o-SPh), 74.6 (CHOH), 61.9*(CSPh), 33.9* (CH2S), 30.6*, 30.45, 29.6*, 28.4*, 26.8*, 26.3*,24.5*, 21.9* and 21.8* (10 × CH2) (Found M�, 324.1594.C18H28OS2 requires M, 324.1581); m/z 324.2 (60%, M), 215.1(30, M � SPh), 191.1 (100, C6H10SPh), 110.0 (90, PhSH) and81.1 (80, C6H9).

Ethyl 3-hydroxy-3-[1�-(phenylsulfanyl)cyclohexyl]propanedithio-ate 8a

n-BuLi (1.77 ml, 1.3 M in hexanes, 2.31 mmol) was added slow-ly to a stirred solution of ethyl dithioacetate 6 (0.25 g, 0.26 ml,2.1 mmol) in THF (10 ml) at �78 �C. The solution was stirredfor 20 min. Aldehyde 7a (0.43 g, 1.95 mmol) in THF (5 ml) wasslowly added. The solution was stirred for 30 min. SaturatedNH4Cl (5 ml) was added and the solution was allowed to warmto room temperature and then extracted with ether (3 × 50 ml).The combined organic extracts were dried (MgSO4) and evap-orated under reduced pressure. The residue was purified byflash chromatography on silica gel eluting with light petroleum(40–60 �C)–ether (9 :1) to give the dithioester 8a (0.35 g, 93%) asa yellow oil; Rf [light petroleum (40–60 �C)] 0.27; νmax (film,CDCl3)/cm�1 3400–3100 (OH) and 1100 (CS2Et); δH(400 MHz,CDCl3) 7.58–7.27 (5 H, m, SPh), 4.03–3.98 (1 H, ddd, J 9.7, 1.5and 3.4, CHOH), 3.66–3.62 (1 H, dd, J 14.3 and 1.4, CHAHBS),3.29–3.24 (2 H, dq, J 12.3 and 7.5, CH2S), 3.21–3.26 (1 H, dd,J 14.4 and 9.7, CHAHBS), 3.10–3.08 (1 H, d, J 7.5, OH), 1.91–1.19 (10 H, m, 5 × CH2) and 1.36–1.32 (3 H, t, J 7.5, CH3);δC(100 MHz, CDCl3) 238.0* (C��S), 137.4 (m-SPh), 130.5*(i-SPh), 129.0 (p-SPh), 128.8 (o-SPh), 76.0 (CHOH), 59.1*(CSPh), 53.4* (CH2C��S), 30.9*, 30.7*, 30.3*, 30.3* and 21.8*(5 × CH2), 26.0* (CH2S) and 12.1 (CH3) (Found M�, 340.0982.C17H24OS3 requires M, 340.0989); m/z 340.1 (45%, M), 231.1(75, M � SPh), 213.1 (50, M � SPh � H2O), 191.1 (90,C6H11SPh), 83.1 (100, C6H12) and 81.1 (80, C6H10).

Ethyl 3-hydroxy-3-[1�-(phenylsulfanyl)cyclopentyl]propane-dithioate 8b

In the same way as 8a, n-BuLi (2.01 ml, 1.3 M in hexanes, 2.62mmol), ethyl dithioacetate 6 (0.28 g, 2.4 mmol) and aldehyde 7b(0.45 g, 2.18 mmol) in THF (50 ml) gave, after column chrom-atography on silica gel eluting with light petroleum (40–60 �C)–ether (9 :1), the dithioester 8b (0.58 g, 82%) as a yellow oil; Rf

[light petroleum (40–60 �C)] 0.30; νmax (film, CDCl3)/cm�1 3300(OH) and 1120 (CS2Et); δH(400 MHz, CDCl3) 7.60–7.25 (5 H,m, SPh), 4.03–3.98 (1 H, dd, J 9.7 and 1.9, CHOH), 3.66–3.62(1 H, dd, J 14.2 and 1.7, CHAHBCS), 3.30–3.22 (2 H, m, CH2S),3.21–3.26 (1 H, dd, J 14.4 and 9.8, CHAHBS), 3.15 (1 H, s, OH),1.91–1.40 (8 H, m, 5 × CH2) and 1.36–1.32 (3 H, t, J 7.5, CH3);δC(100 MHz, CDCl3) 238.1* (C��S), 137.4 (m-SPh), 130.4*(i-SPh), 129.2 (p-SPh), 128.7 (o-SPh), 76.0 (CHOH), 59.1*(CSPh), 53.3* (CH2C��S), 30.9*, 30.7*, 21.8* and 21.8* (4 ×CH2), 26.1* (CH2S) and 12.1 (CH3); m/z 326.1 (50%, M), 217.1(100, M � SPh), 177.1 (80, C5H8SPh).

Ethyl-3-hydroxy-4-methyl-4-phenylsulfanylpentanedithioate 8c

In the same way as 8a, n-BuLi (1.7 ml, 1.3 M in hexane, 2.21mmol), ethyl dithioacetate 6 (0.26 g, 0.27 ml, 2.22 mmol) andaldehyde 7c (0.4 g, 2.22 mmol) in THF (30 ml) gave, after col-umn chromatography on silica gel eluting with light petroleum(40–60 �C)–CH2Cl2 (1 :1), the dithioester 8c (0.51 g, 78%) as anoil; Rf [light petroleum (40–60 �C)–CH2Cl2 (1 :1)] 0.4; νmax (film,CDCl3)/cm�1 1050 (CS2); δH(400 MHz, CDCl3) 7.56–7.30 (5 H,m, SPh), 4.01 (1 H, dt, 9.8 and 1.9, CHOH), 3.48 (1 H, dd,J 14.2 and 1.6, CHAHBCS), 3.27 (2 H, m, CH2S), 3.15 (1 H, d,J 2.7, OH), 3.11 (1 H, dd, J 14.2 and 9.7, CHAHBCS), 1.31 (3 H,t, J 7.4, CH3CH2), 1.30 (3 H, s, CH3) and 1.26 (3 H, s, CH3);δC(100 MHz, CDCl3) 236.0* (C��S), 137.6* (m-SPh), 130.5*

(i-SPh), 129.1 (p-SPh), 128.7 (o-SPh), 75.1 (CHOH), 55.8*(CSPh), 53.4* (CH2C��S), 30.9* (CH2S), 24.6 (CH3), 24.42(CH3) and 12.0 (CH3CH2) (Found M�, 300.0678. C14H20OS3

requires M, 300.0676); m/z 300.1 (75%, M), 238.0 (50, M � CH3-CH2SH), 191.1 (30, M � SPh), 151.1 (100, C3H6SPh) and 110.0(30, PhSH).

3-Hydroxy-3-[1�-(phenylsulfanyl)cyclopentyl]-1-sulfanylpropane9

In the same way as 4, n = 1, the dithioester 8b (0.11 g, 0.35mmol) and LiAlH4 (40 mg, 1.05 mmol) in ether (5 ml) gave,after column chromatography on silica gel eluting with lightpetroleum (40–60 �C)–ether (1 :1), the thiol 9 (85 mg, 83%) asan oil; Rf [light petroleum (40–60 �C)–ether (1 :1)] 0.75; νmax

(film, CDCl3)/cm�1 3200 (OH) and 1550 (SPh); δH(200 MHz,CDCl3) 7.59–7.28 (5 H, m, SPh), 3.62 (1 H, dt, J 8.4 and 5.9,CHOH), 2.86 (1 H, d, J 6.0, OH), 2.71–2.51 (2 H, m, CH2S),1.95–1.51 (10 H, m, 5 × CH2) and 1.38 (1 H, t, J 8.0, SH); δC(50MHz, CDCl3) 136.8 (m-SPh), 131.7 (i-SPh), 129.0 (p-SPh),128.8 (o-SPh), 73.4 (CHOH), 67.3 (CSPh), 36.1 (CH2), 34.8,33.7, 24.8, 22.6 and 22.2 (5 × CH2) (Found M�, 268.0953.C14H20OS2 requires M, 268.0958); m/z 268.1 (5%, M), 177.1 (50,C5H8SPh), 159.1 (10, M � SPh), 110.0 (100, PhSH) and 67.1(95, C5H7).

3-Hydroxy-4-methyl-4-phenylsulfanyl-1-sulfanylpentane 10

In the same way as 4, n = 1, the dithioester 8c (0.5 g, 1.66 mmol)and LiAlH4 (0.12 g, 3.33 mmol) in ether (20 ml) gave, aftercolumn chromatography on silica gel eluting with light petrol-eum (40–60 �C)–ether (9 :1), the thiol 10 (0.31 g, 79%) as an oil;Rf [light petroleum (40–60 �C)–ether (9 :1)] 0.16; νmax (film,CDCl3)/cm�1 3300 (OH); δH(400 MHz, CDCl3) 7.52–7.31 (5 H,m, SPh), 3.44 (1 H, dt, J 9.8 and 2.5, CHOH), 2.95 (1 H, d,J 2.5, OH), 279 (1 H, m, CHAHBS), 2.58 (1 H, m, CHAHBS),1.70 (2 H, m, CH2), 1.37 (1 H, t, J 8.0, SH), 1.24 (3 H, s, CH3)and 1.18 (3 H, s, CH3); δC(100 MHz, CDCl3) 137.4 (m-SPh),130.2* (i-SPh), 129.2 (p-SPh), 128.8 (o-SPh), 73.5 (CHOH),55.2* (CSPh), 35.0* (CH2S), 25.8 (CH3), 23.3* (CH2) and 22.1(CH3) (Found M�, 242.0803. C12H18OS2 requires M, 242.0799);m/z 242.1 (32%, M), 151.1 (100, C3H6SPh) and 109.0 (30, PhS).

4-(Phenylsulfanyl)-1-thiaspiro[4.5]decane 11

Toluene-p-sulfonic acid (6 mg, 30 µmol) was added to a stirredsolution of thiol 4; n = 1 (50 mg, 0.18 mmol) in CH2Cl2 (2 ml).The solution was refluxed for 5 min. The solution was allowedto cool to room temperature and filtered through a silica plug.The solvent was removed under reduced pressure. The residuewas purified by flash column chromatography on silica geleluting with light petroleum (40–60 �C)–ether (9 :1) to give thethiolane 11 (47 mg, 99%) as an oil; Rf [light petroleum(40–60 �C)–ether (9 :1)] 0.34; νmax (film, CDCl3)/cm�1 1600(SPh); δH(400 MHz, CDCl3) 7.47–7.20 (5 H, m, SPh), 3.35–3.29(1 H, dd, J 10.8 and 5.4, CHSPh), 2.92–2.84 (1 H, m, CHAHBS),2.80–2.73 (1 H, m, CHAHBS), 2.52–2.44 (1 H, m, CHAHB-CH2S), 2.25–2.14 (1 H, m, CHAHBCH2S), 2.01–1.92 (1H, dt,J 12.7 and 3.65, CHAHBC) and 1.72–1.20 (9 H, m, CHAHBCand 4 × CH2); δC(100 MHz, CDCl3) 131.9 (m-SPh), 129.0(p-SPh), 126.9 (o-SPh), 76.5* (CSCH2), 62.4 (CSPh), 39.2*(SCH2), 35.4*, 35.0*, 30.9*, 27.4*, 25.7* and 25.6* (6 × CH2)(Found M�, 264.1004. C15H20S2 requires M, 264.1006); m/z264.1 (35%, M), 155.1 (100, M � SPh) and 109 (15, SPh).

TMSOTf mediated rearrangement of the thiol 4, n � 1 to givethiolane 11

TMSOTf (43 mg, 37 µl, 0.18 mmol) was added to a stirredsolution of thiol 4, n = 1 (50 mg, 0.18 mmol) in CH2Cl2 (5 ml) at�78 �C. The solution was then allowed to warm to room tem-perature. Saturated NH4Cl (1 ml) was added and the solution

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was extracted with ether (3 × 10 ml). The combined organicextracts were dried (MgSO4) and evaporated under reducedpressure. The residue was purified by flash column chrom-atography on silica gel eluting with light petroleum (40–60 �C)–ether (1 :1) to give the thiolane 11 (47 mg, 99%) as an oil; identi-cal spectroscopically to that obtained previously.

4-(Phenylsulfanyl)-1-thiaspiro[4.4]nonane 12

In the same way as 11, the thiol 9 (20 mg, 74.6 µmol) andtoluene-p-sulfonic acid (2.6 mg, 1.5 µmol) in CH2Cl2 (1 ml)gave, after column chromatography on silica gel eluting withlight petroleum (40–60 �C)–ether (9 :1), the spirocyclic sulfide12 (18.2 mg, 99%) as an oil; Rf [light petroleum (40–60 �C)–ether (9 :1)] 0.5; νmax (film, CDCl3)/cm�1 3300 (OH); δH(200MHz, CDCl3) 7.47–7.23 (5 H, m, SPh), 3.64 (1 H, dd, J 8.3and 5.1, CHSPh), 3.13–3.34 (2 H, m, CH2S), 2.54–2.37 (1 H,m, CHAHB) and 2.26–1.64 (11 H, 10 × CH2 and CHAHB);δC(100 MHz, CDCl3) 135.9* (i-SPh), 131.6 (m-SPh), 129.0 (o-SPh), 126.9 (p-SPh), 66.0* (CS), 60.4 (CHSPh), 40.4*(CH2S), 37.2*, 36.4*, 28.1*, 24.5* and 24.4* (5 × CH2)(Found M�, 250.0832. C14H18S2 requires M, 250.0849); m/z250.1 (70%, M), 141.1 (100, M � SPh), 109.1 (80, PhS) and67.1 (55, C5H7).

TMSOTf mediated rearrangement of the thiol 9 to give thiolane12

In the same way as 11, the thiol 9 (20 mg, 74.6 µmol) andTMSOTf (16.4 mg, 14 µl, 74.6 µmol) in CH2Cl2 (5 ml) gave,after column chromatography on silica gel eluting with lightpetroleum (40–60 �C)–ether (9 :1), the spirocyclic sulfide 12 (19mg, 99%) as an oil; identical spectroscopically to that obtainedpreviously.

2,2-Dimethyl-3-(phenylsulfanyl)thiolane 13

In the same way as 11, the thiol 10 (50 mg, 0.20 mmol) andtoluene-p-sulfonic acid (3.8 mg, 20 µmol) in CH2Cl2 (1 ml) gave,after column chromatography on silica gel eluting with lightpetroleum (40–60 �C)–ether (9 :1), the spirocyclic sulfide 13 (49mg, 98%) as an oil; Rf [light petroleum (40–60 �C)–ether (9 :1)]0.45; νmax (film, CDCl3)/cm�1 broad 1580 (SPh); δH(400 MHz,CDCl3) 7.55–7.20 (5 H, m, SPh), 3.39 (1 H, dd, J 11.6 and 5.7,CHSPh), 2.94–2.81 (2 H, m, CH2S), 2.57–2.49 (1 H, m,CHAHB), 2.26–2.15 (1 H, m, CHAHB), 1.48 (3 H, s, CH3) and1.42 (1 H, m, CH3); δC(100 MHz, CDCl3) 131.9 (m-SPh), 129.0(o-SPh), 127.0 (p-SPh), 62.2 (CHSPh), 54.0* (CSCH2), 36.1*(CH2S), 29.3 (CH3), 27.6* (CH2) and 27.4 (CH3) (Found M�,224.0696. C12H16S2 requires M, 224.0693); m/z 224.1 (60%, M),135.0 (10, C2H2SPh) and 115.1 (100, M � SPh).

TMSOTf mediated rearrangement of the thiol 10 to give thiolane13

In the same way as 11, the thiol 10 (0.2 g, 0.83 mmol) andTMSOTf (0.18 mg, 0.16 ml, 0.83 mmol) in CH2Cl2 (2 ml) gave,after column chromatography on silica gel eluting with lightpetroleum (40–60 �C)–ether (9 :1), the thiolane 13 (0.18 g, 98%)as an oil; identical spectroscopically to that obtained previously.

4-(Phenylsulfanyl)-1-thiaspiro[4.5]decan-2-one 15

In the same way as 11, the dithioacetate 8a (0.15 g, 0.44 mmol)and toluene-p-sulfonic acid (17 mg, 88 µmol) in CH2Cl2 (2 ml)gave, after column chromatography on silica gel eluting withlight petroleum (40–60 �C)–ether (9 :1), the spirocyclic sulfide 15(0.12 g, 85%) as an oil; Rf [light petroleum (40–60 �C)–ether(9 :1)] 0.2; νmax (film, CDCl3)/cm�1 1150 (CS2); δH(400 MHz,CDCl3) 7.46–7.25 (5 H, m, SPh), 3.72 (1 H, t, J 8.9, CHSPh),2.94 (2 H, double AB quartet, J 9.0, CH2CS) and 2.19–1.20 (10H, m, 5 × CH2); δC(100 MHz, CDCl3) 20.8* (C��S), 134.3*

(i-SPh), 132.7 (m-SPh), 129.3 (p-SPh), 127.9 (o-SPh), 65.6*(CSCH2), 57.6 (CHSPh), 47.9* (CH2C��S), 38.0*, 33.8*, 25.4*,25.1* and 23.4* (5 × CH2); m/z 218 (4%, M � CS2), 136.0 (70,C2H3SPh), 109.1 (100, PhS) and 88.0 (30, CH2(C��S)S).

1-(N,N-Dimethyldithiocarbamoyl)-4-hydroxy-4-[1�-(phenyl-sulfanyl)cyclohexyl]butane 17, n � 2

DEAD (0.12 g, 0.12 ml, 0.71 mmol) was added to a stirredsolution of diol 16, n = 2 (0.1 g, 0.36 mmol), Ziram (0.22 g,0.714 mmol) and PPh3 (0.18 g, 0.71 mmol in toluene (2 ml)).The solution was stirred for 12 hours. The solution was filteredthrough a silica plug and the solvent was removed underreduced pressure. The residue was purified by flash columnchromatography on silica gel eluting with light petroleum (40–60 �C)–ether (1 :1) to give the dithiocarbamate 17, n = 2 (0.11 g,85%) as an oil; Rf [light petroleum (40–60 �C)–ether (1 :1)] 0.55;νmax (film, CDCl3)/cm�1 1254 (C��S); δH(400 MHz, CDCl3) 7.54–7.23 (5 H, m, SPh), 3.50 (3 H, s, NCH3), 3.30 (3 H, s, NCH3),3.28 (3 H, m, CH2S and CHO), 3.05 (1 H, d, J 2.8, OH) and2.05–1.11 (14 H, m, 7 × CH2); δC(100 MHz, CDCl3) 197.4*(C��S), 137.5 (m-SPh), 130.1* (i-SPh), 129.0 (p-SPh), 128.5(o-SPh), 74.4 (CHOH), 61.6* (CSPh), 45.2 (NCH3), 41.4(NCH3), 37.6* (CH2S), 30.5*, 29.8*, 29.7*, 26.6*, 26.2*, 21.8*and 21.6* (7 × CH2) (Found (M � SPh)�, 274.1297. C13H24-OS2N requires M � SPh, 274.1299); m/z 274.1 (35%, M �SPh), 191.1 (20, C6H10SPh), 110.0 (10, PhSH), 88.0 (100,C3H5SN) and 81.1 (20, C6H9).

1-(N,N-Dimethyldithiocarbamoyl)-5-hydroxy-5-[1�-(phenyl-sulfanyl)cyclohexyl]pentane 17, n � 3

In the same way as 17, n = 2, the diol 16, n = 3 (0.21 g, 0.71mmol), Ziram (0.33 g, 1.07 mmol), PPh3 (0.37 g, 1.42 mmol)and DEAD (0.25 g, 0.23 ml, 1.42 mmol) in toluene (3 ml) gave,after column chromatography on silica gel eluting with lightpetroleum (40–60 �C)–ether (1 :1), the dithiocarbamate 17, n = 3(0.23 g, 83%) as an oil; Rf [light petroleum (40–60 �C)–ether(1 :1)] 0.4; νmax (film, CDCl3)/cm�1 1275 (C��S); δH(400 MHz,CDCl3) 7.52–7.25 (5 H, m, SPh), 3.54 (3 H, s, NCH3), 3.32 (3 H,s, NCH3), 3.29–3.19 (3 H, m, CH2S and CHOH), 3.04 (1 H, brs, OH) and 2.02–1.19 (16 H, m, 8 × CH2); δC(100 MHz, CDCl3)197.6* (C��S), 137.2 (m-SPh), 130.2* (i-SPh), 129.0 (p-SPh),128.8 (o-SPh), 74.6 (CHOH), 61.9* (CSPh), 45.2 and 41.4(2 × NCH3), 37.5* (CH2S), 30.6*, 30.1*, 29.6*, 28.8*, 26.7*,26.2*, 21.9* and 21.8* (8 × CH2) (Found M�, 397.1549.C20H31OS3N requires M, 397.1567); m/z 397.2 (10%, M), 288.1(80, M � SPh), 277.2 (10, M � S2CN(CH3)2 � H), 206 (60,M � C6H10SPh), 191.1 (100, C6H10SPh), 121.0 (75, S2CN-(CH3)2), 109 (25, PhSH) and 81.0 (20, C6H9).

1-(N,N-Dimethyldithiocarbamoyl)-6-hydroxy-6-[1�-(phenyl-sulfanyl)cyclohexyl]hexane 17, n � 4

In the same way as 17, n = 2, the diol 16, n = 4 (1.3 g, 4.2 mmol),Ziram (1.92 g, 3 mmol), PPh3 (2.21 g, 8.44 mmol) and DEAD(1.42 g, 1.32 ml, 8.44 mmol) in toluene (15 ml) gave, aftercolumn chromatography on silica gel eluting with light petrol-eum (40–60 �C)–ether (1 :1), the dithiocarbamate 17, n = 4 (1.56g, 90%) as an oil; Rf [light petroleum (40–60 �C)–ether (1 :1)]0.4; νmax (film, CDCl3)/cm�1 1270 (C��S); δH(250 MHz, CDCl3)7.56–7.28 (5 H, m, SPh), 3.53 and 3.34 (6 H, s, 2 × NCH3), 3.25(2 H, t, J 7.3, CH2S), 3.22 (1 H, m, CHOH), 3.07 (1 H, d, J 1.9,OH) and 2.05–1.13 (18 H, m, 10 × CH2); δC(62.5 MHz, CDCl3)197.6* (C��S), 137.2 (m-SPh), 130.1* (i-SPh), 128.9 (p-SPh),128.8 (o-SPh), 74.6 (CHOH), 61.9* (CSPh), 45.1 and 41.40(2 × NCH3), 37.6* (CH2S), 30.6*, 30.4*, 29.6*, 29.1*, 28.5*,27.0*, 26.2*, 21.8* and 21.8* (9 × CH2) (Found M�, 411.1690.C21H33OS3N requires M, 411.1724); m/z 411.1 (50%, M), 302.2(30, M � SPh), 220.1 (45, M � C6H10SPh), 191.1 (50, C6H10-SPh) and 88.0 (100, C3H5NS).

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2-[1�-(Phenylsulfanyl)cyclohexyl]thiolane 18

In the same way as 11, the thiol 4, n = 2 (10 mg, 33.7 µmol) andtoluene-p-sulfonic acid (1.1 mg, 6.7 µmol) in CH2Cl2 (1 ml)gave, after column chromatography on silica gel eluting withlight petroleum (40–60 �C)–ether (9 :1), the thiolane 18 (9.3 mg,99%) as an oil; Rf [light petroleum (40–60 �C)–ether (9 :1)]0.6; νmax (film, CDCl3)/cm�1 1550 (SPh); δH(400 MHz, CDCl3)7.53–7.27 (5 H, m, SPh), 3.56 (1 H, t, J 6.9, CHS), 2.78 (2 H, dd,J 7.7 and 4.8, CH2S) and 2.18–1.20 (14 H, m, 7 × CH2); δC(100MHz, CDCl3) 137.5 (m-SPh), 131.6* (i-SPh), 128.9 (p-SPh),128.7 (o-SPh), 58.9 (CHS), 57.7* (CS), 33.2* (CH2S), 32.5*,31.7*, 31.2*, 31.1*, 26.1*, 21.9* and 21.9* (7 × CH2) (FoundM�, 278.1158. C16H22S2 requires M, 278.1162); m/z 278.1 (70%,M), 191.1 (95, C6H10SPh), 169.1 (100, M � SPh), 87.0 (70,M � C6H10SPh) and 81.1 (30, C6H9).

2-[1�-(Phenylsulfanyl)cyclohexyl]thiane 19

In the same way as 11, the thiol 4, n = 3 (25 mg, 80.6 µmol) andtoluene-p-sulfonic acid (3 mg, 16.1 µmol) in CH2Cl2 (1 ml) gave,after column chromatography on silica gel eluting with lightpetroleum (40–60 �C)–ether (9 :1), the thiane 19 (23.3 mg, 99%)as an oil; Rf [light petroleum (40–60 �C)–ether (9 :1)] 0.75; νmax

(film, CDCl3)/cm�1 1580 (SPh); δH(400 MHz, CDCl3) 7.51–7.22(5 H, m, SPh), 2.72–2.60 (2 H, m, CH2S), 2.59 (1 H, dd, J 12.0and 2.7, CHS) and 2.00–1.23 (16 H, m, 8 × CH2); δC(100 MHz,CDCl3) 137.7 (m-SPh), 131.5* (i-SPh), 128.7 (p-SPh), 128.5(o-SPh), 58.3* (CSPh), 51.5 (CHS), 32.9* (CH2S), 31.8*, 30.2*,29.2*, 27.6*, 27.4*, 25.8* and 22.0* (8 × CH2) (Found M�,292.1318. C17H25S2 requires M, 292.1319); m/z 292.1 (15%, M),191.1 (100, C6H10SPh), 183.1 (70, M � SPh), 109.0 (10, PhSH),109.0 (20, PhSH), 101.0 (60, M � C6H10SPh) and 81.1 (40,C6H9).

6-Cyclohexenyl-6-(phenylsulfanyl)-1-sulfanylhexane 20

In the same way as 11, the thiol 4, n = 4 (30 mg, 92.6 µmol) andtoluene-p-sulfonic acid (3.2 mg, 18.5 µmol) in CH2Cl2 (1 ml)gave, after column chromatography on silica gel eluting withlight petroleum (40–60 �C)–ether (9 :1), the allylic sulfide 20 (27mg, 98%) as an oil; Rf [light petroleum (40–60 �C)–ether (9 :1)]0.9; νmax (film, CDCl3)/cm�1 1600 (SPh); δH(250 MHz, CDCl3)7.34–7.14 (5 H, m, SPh), 5.24 (1 H, br s, CH��C), 3.49 (1 H, t,J 7.6, CHSPh), 2.57 (2 H, t, J 7.2, CH2S), 2.21–1.23 (16 H, m,8 × CH2) and 1.55 (1 H, s, SH); δC(62.5 MHz, CDCl3) 135.7*(C��CH), 135.6* (i-SPh), 133.1 (m-SPh), 128.3 (o-SPh), 126.8(p-SPh), 125.4 (CH��C), 57.2 (CHSPh), 35.6* (CH2S), 32.3*,31.0*, 30.0*, 29.7*, 29.1*, 23.8*, 22.7* and 22.5* (8 × CH2)(Found M�, 306.1478. C18H26S2 requires M, 306.1475); m/z306.1 (95%, M), 197.1 (70, M � SPh), 115.1 (20, M � C6H10-SPh), 109.0 (20, PhS) and 81.1 (55, C6H9).

4-Cyclohexenyl-4-(phenylsulfanyl)butyl N,N-dimethyldithio-carbamate 21, n � 2

In the same way as 11, the dithiocarbamate 17, n = 2 (64 mg,0.16 mmol) and toluene-p-sulfonic acid (5.73 mg, 33.3 µmol) inCH2Cl2 (1 ml) gave, after column chromatography on silica geleluting with light petroleum (40–60 �C)–ether (1 :1), the allylicdithiocarbamate 21, n = 2 (57.9 mg, 95%) as an oil; Rf [lightpetroleum (40–60 �C)–ether (1 :1)] 0.82; νmax (film, CDCl3)/cm�1

1570 (SPh) and 1270 (C��S); δH(250 MHz, CDCl3) 7.40–7.16 (5H, m, SPh), 5.26 (1 H, br s, CH��C), 3.53 (4 H, m, NCH3 andCHSPh), 3.29 (3 H, s, NCH3), 3.26 (2 H, t, J 6.7, CH2S) and2.20–1.41 (12 H, m, 6 × CH2); δC(100 MHz, CDCl3) 197.3*(C��S), 135.3* (C��CH), 133.3 (m-SPh), 129.1* (i-SPh), 128.4(o-SPh), 127.0 (p-SPh), 125.8 (CH��C), 56.8 (CHSPh), 45.2 and41.4 (2 × CH3), 37.2* (CH2S), 31.6*, 26.8*, 25.2*, 23.8*, 22.7*and 22.5* (6 × CH2) (Found M�, 365.1299. C19H27S3N requiresM, 365.1305); m/z 365.1 (5%, M), 277.1 (10, M � C3H5NS),256.1 (80, M � SPh) and 88.0 (100, C3H5NS).

5-Cyclohexenyl-5-(phenylsulfanyl)pentyl N,N-dimethyldithio-carbamate 21, n � 3

In the same way as 11, the dithiocarbamate 17, n = 3 (40 mg, 0.1mmol) and toluene-p-sulfonic acid (3.4 mg, 20 µmol) in CH2Cl2

(1 ml) gave, after column chromatography on silica gel elutingwith light petroleum (40–60 �C)–ether (1 :1), the allylic dithio-carbamate 21, n = 3 (37 mg, 97%) as an oil; Rf [light petroleum(40–60 �C)–ether (1 :1)] 0.8; νmax (film, CDCl3)/cm�1 1280(C��S); δH(250 MHz, CDCl3) 7.48–7.16 (5 H, m, SPh), 5.25 (1 H,s, CH��C), 3.62–3.50 (4 H, m, NCH3 and CHSPh), 3.35 (3 H, s,NCH3), 3.24 (2 H, t, J 7.1, CH2S) and 1.94–1.10 (14 H, m,7 × CH2); δC(62.5 MHz, CDCl3) 210.0* (C��S), 137.0* (C��CH),135.5* (i-SPh), 133.2 (m-SPh), 128.6 (o-SPh), 126.9 (p-SPh),125.9 (CH��C), 57.1 (CSPh), 45.2 and 41.3 (2 × NCH3), 37.4*(CH2S), 32.0*, 28.3*, 27.0*, 25.2*, 23.8*, 22.7* and 22.6*(7 × CH2) (Found M�, 379.1441. C20H29S3N requires M,379.1462); m/z 379.1 (30%, M), 270.1 (70, M � SPh), 110.0 (40,PhSH) and 88.0 (100, C3H5SN).

6-Cyclohexenyl-6-(phenylsulfanyl)hexyl N,N-dimethyldithio-carbamate 21, n � 4

In the same way as 11, the dithiocarbamate 17, n = 4 (50 mg,0.12 mmol) and toluene-p-sulfonic acid (23 mg, 0.12 mmol) inCH2Cl2 (1 ml) gave, after column chromatography on silica geleluting with light petroleum (40–60 �C)–ether (1 :1), the allylicdithiocarbamate 21, n = 4 (45 mg, 96%) as an oil; Rf [lightpetroleum (40–60 �C)–ether (1 :1)] 0.8; νmax (film, CDCl3)/cm�1

3350 (OH) and 1275 (C��S); δH(250 MHz, CDCl3) 7.45–7.18(5 H, m, SPh), 5.36 (1 H, br s, CH��C), 3.53 (3 H, s, NCH3), 3.50(1 H, t, J 7.6, CHSPh), 3.35 (3 H, s, NCH3), 3.26 (2 H, t, J 7.2,CH2S) and 2.28–1.26 (16 H, m, 8 × CH2); δC(62.5 MHz, CDCl3)197.5* (C��S), 135.6* (C��CH), 131.14* (i-SPh), 133.0 (m-SPh),128.7 (o-SPh), 126.8 (p-SPh), 125.4 (CH��C), 57.2 (CHSPh),45.2 and 41.4 (2 × CH3N), 37.5* (CH2S), 32.3*, 28.6*, 28.5*,27.2*, 25.2*, 23.7*, 22.5* and 19.6* (8 × CH2) (Found M�,393.1614. C21H31S3N requires M, 393.1618); m/z 393.2 (20%,M), 284.1 (40, M � PhS), 109.0 (40, PhS) and 88.0 (100,C3H5NS).

4-Cyclohexenyl-4-(phenylsulfanyl)-1-sulfanylbutane 22, n � 2

In the same way as 4, n = 2, the allylic dithiocarbamate 21, n = 2(0.13 g, 0.38 mmol) and LiAlH4 (28 mg, 0.38 mmol) in ether(5 ml) gave, after column chromatography on silica gel elutingwith light petroleum (40–60 �C)–ether (1 :1), the allylic sulfide22, n = 2 (85 mg, 82%) as an oil; Rf [light petroleum (40–60 �C)–ether (9 :1)] 0.8; νmax (film, CDCl3)/cm�1 1550 (SPh); δH(250MHz, CDCl3) 7.46–7.25 (5 H, m, SPh), 5.25 (1 H, br s, CH��C),3.48 (1 H, t, J 7.2, CHSPh), 2.52 (2 H, q, J 7.7, CH2S), 2.19–1.24 (10 H, m, 5 × CH2) and 1.34 (1 H, t, J 7.8, SH); δC(62.5MHz, CDCl3) 133.2* (i-SPh), 133.1* (m-SPh), 128.4 (o-SPh),127.0 (p-SPh), 125.0 (CH��C), 56.8 (CHSPh), 32.5* (CH2S),31.2*, 30.9*, 25.5*, 25.2*, 23.8* and 22.6* (6 × CH2) (FoundM�, 278.1145. C16H22S2 requires M, 278.1162); m/z 278.1 (10%,M), 244.1 (65, M � H2S), 169.0 (50, M � SPh), 110.0 (50,PhSH) and 87.0 (100, C4H7S).

5-Cyclohexenyl-5-(phenylsulfanyl)-1-sulfanylpentane 22, n � 3

In the same way as 4, n = 2, the allylic dithiocarbamate 21, n = 3(50 mg, 0.13 mmol) and LiAlH4 (10 mg, 0.26 mmol) in ether(5 ml) gave, after column chromatography on silica gel elutingwith light petroleum (40–60 �C)–ether (9 :1), the allylic sulfide22, n = 3 (29.2 mg, 76%) as an oil; Rf [light petroleum (40–60 �C)–ether (9 :1)] 0.78; νmax (film, CDCl3)/cm�1 1600 (SPh);δH(250 MHz, CDCl3) 7.35–7.17 (5 H, m, SPh), 5.25 (1 H, br s,CH��C), 3.49 (1 H, t, J 7.5, CHSPh), 2.51 (2 H, q, J 7.2, CH2S)and 2.16–1.20 (14 H, m, 7 × CH2); δC(62.5 MHz, CDCl3) 135.6*(i-SPh), 133.2 (m-SPh), 128.4 (o-SPh), 126.9 (p-SPh), 125.6(CH��C), 57.1 (CHSPh), 33.7* (CH2S), 31.9*, 26.3*, 25.2*,

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2790 J. Chem. Soc., Perkin Trans. 1, 1999, 2783–2790

24.4*, 23.8*, 22.7* and 22.5* (7 × CH2) (Found M�, 292.1319.C17H24S2 requires M, 292.1319); m/z 292.1 (70%, M), 191.1 (45,C6H10SPh), 183.1 (M � SPh), 109.0 (20, PhS) and 87.0 (100,C4H7S).

6-Cyclohexenyl-6-(phenylsulfanyl)-1-sulfanylhexane 20

In the same way as 4, n = 2, the dithiocarbamate 21, n = 4 (20mg, 50 µmol) and LiAlH4 (5.6 mg, 0.15 mmol) in ether (5 ml)gave, after column chromatography on silica gel eluting withlight petroleum (40–60 �C)–ether (1 :1), gave the allylic sulfide20 (10.7 mg, 69%) as an oil; identical spectroscopically to thatobtained previously.

AcknowledgementsWe thank the EPSRC for a grant (to J. E.) and Ray V. H. Jones(Zeneca Process Technology Department, Grangemouth) for aCASE award (to J. E.).

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